SiC heater

Patent metadata

Field	Value
Publication number	US-10966288-B2
Application number	US-201716322425-A
Country	US
Kind code	B2
Filing date	Aug 2, 2017
Priority date	Aug 2, 2016
Publication date	Mar 30, 2021
Grant date	Mar 30, 2021

Abstract

This SiC heater includes a heating element having a thin plate-shaped silicon carbide sintered body and an insulating coat film formed on a surface of the silicon carbide sintered body, a pair of electrodes for conducting electricity in the heating element, and a heater base that holds the heating element from one surface side while insulating the heating element from heat from the heating element, the insulating coat film is located on a surface of the silicon carbide sintered body opposite to the heater base, an electrical resistivity at room temperature of the insulating coat film is 109 Ω·cm or more, a thermal expansion coefficient of the insulating coat film is 2×10−6/K or more and 6×10−6/K or less, SiO2 is included as a matrix, 1% by weight or more and 35% by weight or less of a first additive component including at least one of B2O3 and Al2O3 is contained, and 1% by weight or more and 35% by weight or less of a second additive component including at least one of MgO and CaO is contained.

First claim

The invention claimed is:

1. A SiC heater comprising:
a heating element comprising a thin plate-shaped silicon carbide sintered body and an insulating coat film formed on a surface of the silicon carbide sintered body;
a pair of electrodes for conducting electricity in the heating element; and
a heater base that holds the heating element from one surface side while blocking the heat from the heating element,
wherein the insulating coat film is located on a surface of the silicon carbide sintered body, the surface being on the reverse side of the heater base-side surface,
an electrical resistivity at room temperature of the insulating coat film is 10 9 Ω·cm or more,
a thermal expansion coefficient of the insulating coat film is 2×10 −6 /K or more and 6×10 −6 /K or less,
the insulating coat film is consisting essentially of a matrix and first and second additive components added to the matrix,
the matrix is SiO 2 ,
the first additive component is one or both of B 2 O 3 and Al 2 O 3 ,
the second additive component is one, two or three of BaO, MgO and CaO and includes at least one of MgO and CaO,
a proportion of the first additive component is 1% by weight or more and 35% by weight or less of a total weight of the insulating coat film,
a proportion of the second additive component is 1% by weight or more and 35% by weight or less of the total weight of the insulating coat film.

2. The SiC heater according to claim 1 ,
wherein the second additive component includes both of MgO, and CaO.

3. The SiC heater according to claim 2 ,
wherein the second additive component includes all of BaO, MgO, and CaO.

4. The SiC heater according to claim 3 ,
wherein a total of contents of MgO and CaO of the second additive component is equal to or more than and twice or less than a content of BaO.

5. The SiC heater according to claim 1 ,
wherein a shape of the heating element is a substantial S shape in a plan view having two slits notched from two facing sides of a substantially square shape or a substantially rectangular shape in a plan view toward opposite sides respectively, and both end portions of the substantial S shape are respectively connected to the pair of electrodes.

6. The SiC heater according to claim 1 ,
wherein the insulating coat film is made of at least one of borosilicate glass or aluminosilicate glass.

7. The SiC heater according to claim 1 ,
wherein a proportion of the first additive component is 1% by weight or more and 30% by weight or less of the total weight of the insulating coat film.

8. The SiC heater according to claim 1 ,
wherein a sintered body density of the silicon carbide sintered body is 2.5 g/cm 3 or more, and an electrical resistivity at 25° C. is 0.1 Ω·cm or more and 100 Ω·cm or less.

9. The SiC heater according to claim 2 ,
wherein a shape of the heating element is a substantial S shape in a plan view having two slits notched from two facing sides of a substantially square shape or a substantially rectangular shape in a plan view toward opposite sides respectively, and both end portions of the substantial S shape are respectively connected to the pair of electrodes.

10. The SiC heater according to claim 2 ,
wherein the insulating coat film is made of at least one of borosilicate glass or aluminosilicate glass.

11. The SiC heater according to claim 2 ,
wherein a proportion of the first additive component is 1% by weight or more and 30% by weight or less of the total weight of the insulating coat film.

12. The SiC heater according to claim 2 ,
wherein a sintered body density of the silicon carbide sintered body is 2.5 g/cm 3 or more, and an electrical resistivity at 25° C. is 0.1 Ω·cm or more and 100 Ω·cm or less.

13. The SiC heater according to claim 3 ,
wherein a shape of the heating element is a substantial S shape in a plan view having two slits notched from two facing sides of a substantially square shape or a substantially rectangular shape in a plan view toward opposite sides respectively, and both end portions of the substantial S shape are respectively connected to the pair of electrodes.

14. The SiC heater according to claim 3 ,
wherein the insulating coat film is made of at least one of borosilicate glass or aluminosilicate glass.

15. The SiC heater according to claim 3 ,
wherein a proportion of the first additive component is 1% by weight or more and 30% by weight or less of the total weight of the insulating coat film.

16. The SiC heater according to claim 3 ,
wherein a sintered body density of the silicon carbide sintered body is 2.5 g/cm 3 or more, and an electrical resistivity at 25° C. is 0.1 Ω·cm or more and 100 Ω·cm or less.

17. The SiC heater according to claim 4 ,
wherein a shape of the heating element is a substantial S shape in a plan view having two slits notched from two facing sides of a substantially square shape or a substantially rectangular shape in a plan view toward opposite sides respectively, and both end portions of the substantial S shape are respectively connected to the pair of electrodes.

18. The SiC heater according to claim 4 ,
wherein the insulating coat film is made of at least one of borosilicate glass or aluminosilicate glass.

19. The SiC heater according to claim 4 ,
wherein a proportion of the first additive component is 1% by weight or more and 30% by weight or less of the total weight of the insulating coat film.

20. The SiC heater according to claim 4 ,
wherein a sintered body density of the silicon carbide sintered body is 2.5 g/cm 3 or more, and an electrical resistivity at 25° C. is 0.1 Ω·cm or more and 100 Ω·cm or less.

Assignees

• Sumitomo Osaka Cement Co Ltd

Inventors

• Nagatomo Hiroaki
• Uchikawa Yuki
• Murakami Yoshihiko

Classifications

• C03C3/091 Primary

  containing aluminium · CPC title

• H05B3/14

  the material being non-metallic · CPC title

• C04B35/575

  obtained by pressure sintering · CPC title

• H05B3/12

  characterised by the composition or nature of the conductive material · CPC title

• C04B2235/5409

  expressed by specific surface values · CPC title